An international group of investigators has been meeting periodically since 1969 to discuss research in the field of volume regulation and hypertension. Initially, the group focused its discussions on "natriuretic hormone" , a putative circulating factor regulating renal sodium excretion. Subsequently, the focus enlarged to include those issues generated by the discovery of endogenous digitalis-like factor (DLF) and its possible role in the pathophysiology of hypertension. The proposal is for support of a meeting entitled "Natriuretic and Na-K- ATPase Inhibiting Factors in Hypertension" to be held June 1,2 at the Hyatt Regency Hotel in San Francisco. The meeting will be an official satellite of the annual meeting of the American Society of Hypertension and will be held in the two days immediately following ASH. On the first day of he two-day meeting, the program will begin with two state-of-the-art talks. As in previous meeting of this group, most of the time will be spent on presentations of recently acquired data by leading investigators in the field. The themes of the 1997 symposium will be similar to those of the 1992 symposium in Seville, Spain, with an emphasis on new developments. The themes have as their common ancestor the hypothesis that renal sodium excretion is regulated by a natriuretic hormone that inhibits sodium transport. From this idea, three areas of investigation have evolved which will be emphasized: elucidation for the structure of DLF found in mammalian species; the role of DLF in the pathophysiology of hypertension; and the actions DLF.